Inclinometer



Nov. 3, 1931, 1 M D HETTRICK 1,829,990

INCLINOMETER Filed Jan. s, 1928 2 Sheets-Sheet 1 INVENTOR ATTORNEY Patented Nov. 3, 1931 UNITED STATES MAURICE D. I-IETTRICK, OF YELM, WASHINGTON INCLINOMETER Application filed January 3, 1928. Serial No. 244,274.

This invention relates to an indicator, the general object of the invention being to provide means for indicating when an airship is level or is tilted about its longitudinal center and about its transverse center.

Another object of the invention is to provide means for indicating when the ship is upside down.

This invention also consists in certain other features of construction and in the combination and arrangement of the several parts, to be hereinafter fully described, illustrated in the accompanying drawings and specifically pointed out in the appended claim.

In describing my invention in detail, reference will be had to the accompanying drawings wherein like characters denote like or corresponding parts throughout the several views, and in which Figure 1 is an elevation of the device.

Figure 2 is a section on line 22 of Figure 1.

Figure 3 is a section on line 3-3 of Figure 1. V

Figure 4 is an elevation with the cover removed.

Figure 5 is a perspective view of the weighted cylinder.

Figure 6 is a sectional view through portion of the circular bubble glass.

Figures 7 and 8 are diagrammatic views.

As shown in these views, the device comprises a base 1 which is adapted to be fas tened to a part of the instrument board of an aircraft or this base may form part of such board. An opening 2 is made in said base or board and brackets 3 are fastened to its rear face on horizontally opposite sides of the opening. These brackets carry pointed screws 4, the pointed ends of which engage recesses in a threaded shaft 5 so that the shaft is rotatably supported by said screws. A cylinder or drum 6 is carried by said shaft and is adjustably mounted thereon by the nuts 7 engaging the shaft and clamping the cylinder between them. The circumference of the cylinder is provided with the indications 8 which cooperate with themarker 9 of U-shape and attached to the board in front of the cylinder for indicating whether or not the ship is on an even keel. The cylinder is provided with a weight 10 which tends to hold it in a certain position under the action of gravity and the indications are, so arranged that when the ship is on an even keel the word level on the cylinder will be in alignment with the marker 9. If the nose of the ship tilts downwardly the cylinder will turn through the action of gravity and the indications will indicate the degree/of tilt. If the nose tilts upwardly the cylinder will turn in an opposite direction and the indications will give the amount of this tilt. I prefer to make the lower half of the cylinder of red color so that if the ship should turn entirely over this red port-ion will come opposite the marker and thus the pilot will knowthat he is traveling upside down and the-indications on this part of the cylinder will tell'him the degree of tilt or the fact that he is traveling horizontally though upside down.

I also provide means for indicating when the ship tilts about its longitudinal center, such means consisting of a ring-shaped bubble glass 10 placed on the base 1 and surrounding the opening 2. This glass is held in place by the clips 11. A dial 11 is placed on the base 1 under the bubble glass and the lower portion of this dial is colored red so as to indicate when the ship has turned over. This dial contains the legends 12 for indicating when the wings are tilted up and the degree of such tilt, as clearly shown in Figures 4, 7 and 8. I provide a transparent .3 cover 14 for the device which is hingedly connected with the base, as shown at 15, and has fastening means 16 for fastening it in closed position. As shown, such means consists of a bracket on the base and a bracket on the ring of the cover, with a screw connecting the two brackets together.

From the foregoing it will be seen that I have provided means whereby a pilot of an aircraft can readily tell when the ship tilts about its longitudinal center or about its transverse center and the degree of such movements. It also tells him when he has turned completely over.

It is thought from the foregoing descrip- U Cit tion that the advantages and novel features of my invention will be readily apparent.

I desire it to be understood that I may make changes in the construction and in the combination and arrangement of the several parts, provided that such changes fall Within the scope of the appended claim.

Vhat I claim is An inclinometer comprising a base rigidly secured to the dash of an aeroplane and having an opening, L-shaped brackets secured to the rear face of the base at opposite sides of the opening, pointed adjusting screwthreaded members threaded to the brackets with the pointed ends opposing each other, a rotatable screw-threaded shaft having socketed ends receiving the pointed ends of the adjusting screws and traversing the opening, a cylinder having one end closed by a centrally apertured end Wall mounted on the shaft, adjusting nuts on the shaft and engaging opposite faces of the end Wall of the cylinder to permit adjustment of the cylinder end- Wise of the shaft and relative to the opening, said cylinder having graduations on the periphery thereof and a portion of the cylinder extending through the opening, a substantially U-shaped marker secured to the base and overlying the opening and the portion of the-cylinder extending through the opening, and a transparent panel-removably secured to the base and overlying the marker and the portion of the cylinder adjacent thereto.

In testimony whereof I affix my signature.

MAURICE D. HETTRIGK. 

